Pitcher Carlos Martinez has since removed the offending links. As of 4:30 p.m. Tuesday, the 22-year-old had 20,900 followers, and had tweeted 362 times.

The Cardinals organization learned about the content of Martinez's Twitter feed on Monday – before the Deadspin post was published, according to MLB.com.

In a telephone interview, Cardinals General Manager John Mozeliak said team is very clear with the players every day on the topic of what is appropriate on social media and what isn't.

"He made a poor decision from some degree on what he was doing," says Mozeliak. "It also sounds like he may have been hacked too from my understanding on how much was involved in all of this. So guys have to be smarter."

Social media experts say Martinez's plight is indicative of what can happen when people aren't paying attention to what's on their social media pages.

As for what you should post on social media?

"Twitter and Facebook and even Youtube are best for positive and informative messages," said Lelani Carver, a Maryville University communications professor. "Not necessarily messages that are negative or private."